It is proposed to study the subclinical injuries to the brain, brainstem and spinal cord due to the forced acceleration of the head and neck through a functional evaluation of its state. Previous studies in our laboratory have reported on the presence of subcortical spikes in primates as a result of whiplash, which were not visible on the scalp EEG. Rhesus monkeys with visible postwhiplash EEG spiking from implanted depth electrodes have been used to develop digital matched filters which are capable of detecting these same spikes in the scalp EEG. The main features of these digital filters are to characterize the normal background noise at the scalp, i.e., the on-going spontaneous EEG there and then to design an optimum filter which is capable of detecting any subcortical event as well as any other concomitant phenomena caused by these subcortical events, in the scalp EEG. We would like to continue these studies by increasing the population as well as refine our methods of procedure. Based on the invasive animal work, we hope to apply the corresponding noninvasive technique to human patients. In processing the scalp signal alone, we hope to statistically infer the presence of the deep events postwhiplash first in the rhesus and later in human patients. Similar electrodiagnosis in humans is, at this point, assumed valid since the variations in clinically observable symptoms are seen in the primates. We also hope to correlate the subcortical EEG data with the accurately measured mechanical input in order to propose and validate new or supplementary tolerance standards for the rhesus, and through certain existing scaling laws, to humans as well.